The implications of these considerations justify the statement that all empirically verifiable knowledge even the commonsense knowledge of everyday life – involves implicitly, if not explicitly, systematic theory in this sense. – Talcott Parsons

It is probably safe to say that all the changes of factual knowledge which have led to the relativity theory, resulting in a very great theoretical development, are completely trivial from any point of view except their relevance to the structure of a theoretical system. – Talcott Parsons

From all this it follows what the general character of the problem of the development of a body of scientific knowledge is, in so far as it depends on elements internal to science itself. – Talcott Parsons